Bubble Shaped Membrane and Use of Such Membrane in a Device

Abstract

The invention relates to a membrane ( 17 ) completely covering an opening ( 13 ) giving access to a space in a device which membrane ( 17 ) is made of an elastic material penetrable by a needle, the membrane ( 17 ) is fastened around the opening ( 13 ) and the membrane ( 17 ) protrudes from the opening ( 13 ) and forms an air filled volume in front of the opening ( 13 ) which air filled volume can be reduced in size when a pressure is put on the membrane ( 17 ) from the outside, the inner surfaces of the membrane ( 17 ) define a passage ( 17 a ) at the first closed end of the membrane ( 17 ) through which a needle ( 19 ) can pass and the second end of the membrane ( 17 ) is adapted to attach the membrane ( 17 ) to a holding part ( 61 ). The walls of the membrane ( 17 ) have a thickness and shape of the chosen membrane material making it possible, to maintain the protruding shape in a use position without the outer surfaces of the membrane ( 17 ) are supported with walls of rigid material. Also the invention relates to a device in which the membrane is used, and a kit where this device is combined with a corresponding unit.

1 . A membrane ( 17 ) completely covering an opening ( 13 ) giving access to a space in a device which membrane ( 17 ) is made of an elastic material penetrable by a needle, the membrane ( 17 ) is fastened around the opening ( 13 ) and the membrane ( 17 ) protrudes from the opening ( 13 ) and forms an air filled volume in front of the opening ( 13 ) which air filled volume can be reduced in size when a pressure is put on the membrane ( 17 ) from the outside, the inner surfaces of the membrane ( 17 ) define a passage ( 17   a ) at the first closed end of the membrane ( 17 ) through which a needle ( 19 ) can pass and the second end of the membrane ( 17 ) is adapted to attach the membrane ( 17 ) to a holding part ( 61 ), characterized in that the walls of the membrane ( 17 ) have a thickness and shape of the chosen membrane material making it possible, to maintain the protruding shape in a use position without the outer surfaces of the membrane ( 17 ) being supported with walls of rigid material. 
     
     
         2 . A membrane according to  claim 1 , wherein the second end of the membrane ( 17 ) has an internal opening ( 17   b ) fitting around the outer contour of a protruding part ( 61   a ) on the holding part ( 61 ) and that the membrane ( 17 ) is fastened to the holding part ( 61 ) by interference fit. 
     
     
         3 . A membrane according to  claim 1  or  2 , wherein the membrane ( 17 ) is supported with walls of a rigid material on the inner surfaces of the membrane ( 17 ) e.g. in the form of a penetrating needle. 
     
     
         4 . A membrane according to  claim 1 ,  2  or  3 , wherein the cross-section of the air-filled volume in the passage ( 17   a ) is smaller than  2 ·[max cross-section of the opening ( 13 )]. 
     
     
         5 . A membrane according to any preceding claim, wherein the membrane ( 17 ) has a constant or decreasing outer cross-section from where the membrane ( 17 ) is attached to the device and to the proximal end, and the passage ( 17   a ) is formed by increasing the thickness of the walls of the membrane ( 17 ) at the proximal end of the membrane ( 17 ) thereby reducing the inner air-filled cross-section of the membrane ( 17 ). 
     
     
         6 . A membrane according to any preceding claim, wherein the properties of the material forming the membrane ( 17 ) forming folding sections and making it possible to predict how the air filled volume is reduced when subjected to an external pressure. 
     
     
         7 . A membrane according to any of the preceding claims, wherein the membrane ( 17 ) can be penetrated by a pointy needle. 
     
     
         8 . A membrane according to any of the preceding claim, wherein the material of the membrane ( 17 ) positioned closest to the device has the thickness b 1  and has the form of a hollow truncated cone or a cylinder and the material positioned furthest away from the device has a thickness b 2  and has the form of a hollow cylinder which is closed at the end opposite the device, and b 2 >b 1 . 
     
     
         9 . A membrane according to  claim 8 , wherein a part of the membrane ( 17 ) positioned between the material closest to the device having the thickness b 1  and the material positioned furthest away from the device having a thickness b 2 , has a thickness varying from b 1  to b 2 . 
     
     
         10 . A membrane according to  claim 8  or  9 , wherein b 2 ≧1.5·b 1 . 
     
     
         11 . A membrane according to any of the  claims 3 - 7 , wherein b 2 <b 1  and the distance between the rigid material supporting the inner surfaces of the membrane ( 17 ) and the inner surfaces of the membrane ( 17 ) is less than 0.5 mm. 
     
     
         12 . A device comprising
 a membrane ( 17 ) according to any of the  claims 1 - 11 ,   a base part which base part comprise a surface plate ( 1 ), fastening means which fasten the base part to a subject, a fluid path ( 3 ) having at least two openings ( 12 ,  13 ): an inlet and an outlet for fluid, where one opening ( 13 ) is protected by the membrane ( 17 ) and the second opening during use connects to a penetrating part ( 7 ) transferring fluid to and/or from the subject in which it is inserted.   
     
     
         13 . A device according to  claim 12 , wherein the opening ( 13 ) is provided at the end of a needle ( 19 ) which needle ( 19 ) is fastened unreleasably to the device and the needle ( 19 ) is placed in the air filled volume inside the membrane ( 17 ) and during periods where no pressure is put on the membrane ( 17 ) the part of the needle ( 19 ) extending into the air filled volume is completely surrounded by air. 
     
     
         14 . A device according to  claim 13 , wherein the needle ( 19 ) during periods where pressure is put on the membrane ( 17 ) extends through the membrane ( 17 ) and protrudes from the outer surface of the membrane ( 17 ). 
     
     
         15 . A device according to  claim 12 ,  13  or  14 , wherein the needle ( 19 ) is a pointy needle. 
     
     
         16 . A device according to  claim 12 ,  13 ,  14  or  15 , wherein the penetrating part ( 7 ) comprises a cannula ( 22 ). 
     
     
         17 . A kit comprising a device comprising a membrane according to any of the  claims 1 - 11  and a unit adapted to be joined to the device assuring a sterile transfer of fluid between the device and the joined unit.